翠柏属 cui bai shu [Chinese].
A genus generally agreed to include four species:
Syn: Heyderia K. Koch; Libocedrus sensu Bentham et Hooker pro parte (Vidakovic 1991).
Trees evergreen, large. Branchlets flattened, in fan-shaped flattened sprays. Leaves opposite in 4 ranks (although apparently in whorls of 4). Adult leaves dimorphic, appressed, overlapping, scalelike, lateral leaves overlapping facial leaves, free portion of long-shoot leaves to ca. 3 mm; abaxial glands present. Staminate and ovuliferous cones monoecious, on different branchlets, rarely dioecoius. Staminate cones oblong, with 6-8 pairs of sporophylls, each sporophyll with 4 pollen sacs. Ovulate cones maturing and opening first year, ellipsoid, 17-30 mm; scales persistent, mucronate at the apex, (2)3 pairs, oblong and basifixed, valvate, woody; proximal pair reduced, sterile, often reflexed or lacking; median pair much longer, oblong, and fertile; distal pair if present connate into an erect partition, sterile. Seeds 2 per scale, lenticular, with one short and one long wing, nearly equaling the scale; cotyledons 2. x = 11 (Li 1975, Thieret 1993).
W USA & Mexico, SW China & Myanmar, Vietnam, and Taiwan (Li 1975, Averyanov et al. 2005). This is a common distribution pattern in relictual Tertiary conifers; related examples include the species of Chamaecyparis and of Thuja, and the Metasequoia-Sequoia-Sequoiadendron group. In each case ancient floristic affinities exist that date back to the Cretaceous breakup of Laurasia, coupled with more recent direct geographic connection across the Bering Land Bridge (which, evolutionarily speaking, is only temporarily out of service) and similarities of climate between east Asia and temperate North America. Several groups of holarctic conifers also show similar close affinities between the west and northeast portions of the Pacific rim, including Abies sect. Balsamea, most of the genus Picea, Pinus subsect. Strobus, and much of the genus Taxus.
Probably C. decurrens, but there are few data on the other species.
A very small amount of work has been done with C. decurrens, which forms many false rings but can sometimes be dated using densitometric methods (Dobry and Kyncl 1992) or ring widths (chronologies by King and Graumlich, 1990, on file with the WDC for Paleoclimatology. None of the other species appear to have been used in dendrochronology.
As with so many species of Cupressaceae, the wood is soft but highly resistant to decay, fragrant, and easily worked. The two common species, C. decurrens and C. macrolepis, have therefore been used for construction and for finer work such as furniture and finish carpentry. They are also widely planted as ornamentals. The two rare species, C. funebris and C. rupestris, would likely be put to similar uses, but I have found no record of the ethnobotanical uses of those taxa.
See the species descriptions.
Named from Greek: callos, beautiful, and kedros, cedar (Thieret 1993).
Dobry, J., and J. Kyncl. 1992. Tree-ring density profiles in Cupressaceae. Pp. 83-84 in T.S. Bartholin, B.E. Berglund, D. Eckstein, F.H. Schweingruber, and O. Eggertsson (eds.), Tree Rings and Environment: Proceedings of the International Symposium, Ystad, South Sweden, 3-9 September, 1990. Department of Quaternary Geology, Lund University, Sweden: Lundqua Report 34.
Kurz, S. 1873. On a few new plants from Yunan. Journal of Botany 11:193-196, t. 133. Available: Biodiversity Heritage Library, accessed 2012.11.25.
Farjon (2005) provides a detailed account, with illustrations.
Last Modified 2017-12-29